Aside from its protective function, our skin plays other roles in signaling subtleties – whether it’s a flush of embarrassment or a fluttering heart. Now, engineers at StanfordUniversity have figured out a comfortable way to collect these physiological data from the skin.

Imagine a skin-hugging sensor that not only tracks your health but also uses a unique radio frequency identification (RFID) to beam the data back to receivers on your clothing.

That’s what the Stanford researchers developed, and they’re calling it BodyNet.

So, how does this wearable technology work?

The researchers equipped a volunteer with abdomen and wrist sensors to examine how the skin contracts and relaxes. Using the data they collected, the team were able to determine the person’s respiration and pulse.

Similarly, sticking the sensors on the volunteer’s elbows and knees provided data on how the muscles flex. As a result, the researchers were able to monitor the leg motion.

According to Zhenan Bao, a chemical engineering professor at Stanford University, this could be the first wearable to be used in medical settings.

Its application ranges from monitoring patients with heart conditions and those with sleeping disorders.

“We think one day, it will be possible to create a full-body skin-sensor array to collect physiological data without interfering with a person’s normal behavior.”

Using BodyNet to Track Respiration and Heart Rate

BodyNet is a skin-hugging sensor that not only tracks your health but also uses a unique RFID to beam the data back to receivers on your clothing. | Image Credit: Bao lab

Postdoctoral scholars Simiao Niu and Naoji Matsuhisa dreamed of creating wearables without batteries. The said wearable should not only stretch and contract with the skin, but it must be comfortable to wear too.

After three years, the 14-person team finally arrived at a design that met these parameters — a sticker that uses a variation of RFID technology to beam information from the sensor to a receiver on the user’s clothing.

To make the wireless sticker comfortable and stretchy, the researchers had to create an antenna that’s just as flexible as the human skin. So, they screen-printed metallic ink on rubber stickers.

The problem with this method was that the bending and stretching movements made the antenna signal too weak or unstable to use.

As a solution, the Stanford engineers developed a new type of RFID system to beam reliable and accurate signals to the battery-powered receiver. Then, the receiver could upload the data from the stickers to a smartphone or computer.

While the initial versions of the BodyNet only provided respiration and pulse reading, the researchers are looking to improve it. For example, they’re working on one that integrates temperature and sweat sensors into the system.

This could take the tech beyond medical monitoring to consumer-friendly devices. Perhaps in the future, we could depend on items of clothing with embedded sensors while exercising.